I didn't expect to see a thread like this. Sure, here's some info..
I use a
Filastruder to do the extrusion. I also have the winder, but it's not required. I used the extruder to make coils on the floor without any issue. I like the winder as it makes the whole thing need less space. Without it, you need about a 4 foot diameter area under the extruder with no obstructions. You also get more consistent diameter filament with the winder. I make 3mm filament, well, the nozzles come undersize so at the moment I make 2.65mm filament +/- 0.1 or so. I have some drill bits coming to enlarge the nozzle a bit, but it works well for me at 2.65. I just have to tighten the tensioner on the printer a bit. The trick is to avoid going too big, or you jam your printer.
20 lb Virgin ABS resin/Pellets for injection molding, White Polylac PA-746 <-- Oh.. didn't know the forum would get the title of the page. Fancy.
Those are the cheapest ABS pellets I've found. They extrude cleanly and print a light grey. You can also mix colorants in, but getting an even color can be tricky. The pros run it though, then chop it up and run a second time to mix it in better. You can build a setup to do that pretty cheaply. I've seen a number of people intentionally make multi-color filament instead. It makes an interesting look when printed. Kind of a tie-dye effect. ABS colorants are available in all sorts of colors from many places. They are also commonly known by the brand name Masterbatch.
The one thing I would like to be able to do that I can't right now is to recycle prints. The extruder needs small pellets to work, about 5mm^3. Shredding a part, particularly a high-infill one, requires thick steel blades and a lot of torque. I've seen some groups try to market one, but they run about $300, and are hand-cranked. A few people have tried blenders etc, but they don't do a great job and it's really hard on the blender. It's also recommended to use no more than 20% recycled plastic as it develops some issues after being cycled over and over. There have been a couple people that are working with Harbor Freight wood chippers at about $100. Maybe something will come out of that. All that combined with $2/lb ABS makes it really hard to justify personal recycling from a financial perspective. If someone has access to a laser cutter or water-jet and wants to make me some cheap blades, there are open source designs though....